New treatment options are badly needed for acute myeloid leukemia, a relatively rare form of cancer. The malignancy begins in the bone marrow, and from there can spread rapidly to the bloodstream, depriving the body of the essential blood cells that carry oxygen and fight infections.
Now, new work from a team lead by Rockefeller University researchers has revealed a potential genetic weakness of the disease, offering insights into the molecular mechanisms behind acute myeloid leukemia and suggesting a new target for drug development.
The image shows cancerous mouse bone marrow cells generated by the mutant protein AE, found in 15 percent of acute myeloid leukemia patients. Using AE as an entry point, the researchers found another protein that prompts similar changes in gene activation.
Credit: Laboratory of Biochemistry and Molecular Biology at The Rockefeller University/Nature
Previously, researchers identified a variety of mutations associated with this disease, including a DNA rearrangement found in about 15 percent of patients. The abnormal DNA-binding protein produced as a result of this mutation takes on entirely new functions, dramatically altering a set of genes that are turned on in a cell to promote the cancer. But how this mutation affects these changes has remained mysterious.
In their new work published on October 21 in Genes and Development, the researchers describe how they identified the molecular mechanism behind this gene activation.
The researchers, led by Robert G. Roeder, Arnold and Mabel Beckman Professor and head of Rockefeller's Laboratory of Biochemistry and Molecular Biology, began by searching for proteins that interact with the mutant protein, known as AE, produced by a DNA rearrangement. Their screen identified JMJD1C, an enzyme that removes chemical tags, known as methyl groups, from histones, which are proteins contained in chromosomes. These tags serve as repressive marks, indicating that genes in the associated region should be turned off.
To investigate the relationship between JMJD1C and AE, the team first explored the broader effects of removing JMJD1C. "We found that numerous genes were down-regulated upon loss of JMJD1C, and the set overlaps significantly with the genes that are normally activated by AE," explains first author Mo Chen, a postdoc in Roeder's lab.
The loss of gene expression turns out to have dramatic consequences for the disease. The team found that acute myeloid leukemia cells are addicted to the presence of JMJD1C, and without it they cannot survive. "In fact, these cells were very sensitive to depletion of JMJD1C," says Chen. "We see an increase in apoptosis, a sort of cellular suicide."
The team confirmed that JMJD1C interacts with AE, and demonstrated that the enzyme is required for AE to exert its cancer-promoting effects. But they also found that JMJD1C plays an even a broader role in acute myeloid leukemia, beyond its interaction with AE.
"We were very surprised to find that JMJD1C is required for the proliferation of other acute myeloid leukemia cell lines, which do not have AE, so we looked for other proteins that might be responsible for JMJD1C addiction," says Chen. The team found at least two other proteins that can recruit JMJD1C to target genes in diseased cells that lack AE, fueling leukemia growth.
These results suggest that JMJD1C may play a general role in promoting growth in myeloid leukemias, according to the researchers. "We are excited because this type of general phenomena is an ideal target for drug development," Roeder says.
There are already small molecules that inhibit this class of enzymes. "Our work will facilitate the development of selective inhibitors against JMJD1C, which is a highly promising therapeutic target for multiple types of leukemia," Roeder adds.
Wynne Parry | EurekAlert!
Solving the efficiency of Gram-negative bacteria
22.03.2019 | Harvard University
Bacteria bide their time when antibiotics attack
22.03.2019 | Rice University
DESY and MPSD scientists create high-order harmonics from solids with controlled polarization states, taking advantage of both crystal symmetry and attosecond electronic dynamics. The newly demonstrated technique might find intriguing applications in petahertz electronics and for spectroscopic studies of novel quantum materials.
The nonlinear process of high-order harmonic generation (HHG) in gases is one of the cornerstones of attosecond science (an attosecond is a billionth of a...
Nano- and microtechnology are promising candidates not only for medical applications such as drug delivery but also for the creation of little robots or flexible integrated sensors. Scientists from the Max Planck Institute for Polymer Research (MPI-P) have created magnetic microparticles, with a newly developed method, that could pave the way for building micro-motors or guiding drugs in the human body to a target, like a tumor. The preparation of such structures as well as their remote-control can be regulated using magnetic fields and therefore can find application in an array of domains.
The magnetic properties of a material control how this material responds to the presence of a magnetic field. Iron oxide is the main component of rust but also...
Due to the special arrangement of its molecules, a new coating made of corn starch is able to repair small scratches by itself through heat: The cross-linking via ring-shaped molecules makes the material mobile, so that it compensates for the scratches and these disappear again.
Superficial micro-scratches on the car body or on other high-gloss surfaces are harmless, but annoying. Especially in the luxury segment such surfaces are...
The Potsdam Echelle Polarimetric and Spectroscopic Instrument (PEPSI) at the Large Binocular Telescope (LBT) in Arizona released its first image of the surface magnetic field of another star. In a paper in the European journal Astronomy & Astrophysics, the PEPSI team presents a Zeeman- Doppler-Image of the surface of the magnetically active star II Pegasi.
A special technique allows astronomers to resolve the surfaces of faraway stars. Those are otherwise only seen as point sources, even in the largest telescopes...
Researchers at Chalmers University of Technology and the University of Gothenburg, Sweden, have proposed a way to create a completely new source of radiation. Ultra-intense light pulses consist of the motion of a single wave and can be described as a tsunami of light. The strong wave can be used to study interactions between matter and light in a unique way. Their research is now published in the scientific journal Physical Review Letters.
"This source of radiation lets us look at reality through a new angle - it is like twisting a mirror and discovering something completely different," says...
11.03.2019 | Event News
01.03.2019 | Event News
28.02.2019 | Event News
22.03.2019 | Life Sciences
22.03.2019 | Life Sciences
22.03.2019 | Information Technology